Procedures

Valve gear, servicing

Note:
^ Cylinder heads which have cracks between the valve seats or between valve seat inserts and the spark plug thread can be used further without reducing service life, provided the cracks do not exceed a maximum of 0.3 mm in width, or when no more than the first 4 turns of the spark plug threads are cracked.
^ After installing camshafts wait for approximately 30 minutes before starting engine. Hydraulic valve compensation elements have to settle (otherwise valves will stake pistons).
^ After working on the valve gear, turn the engine carefully at least 2 full rotations by hand to ensure that none of the valves make contact when the starter is operated.
^ Replace all seals, gaskets and O-rings.





1 - Double bearing cap
^ Lightly coat contact surfaces of front and rear bearing caps with sealant before installation; Refer to Fig. 2
^ Use liquid sealant
^ Refer to Part Supplier
2 - 5 Nm - tighten 90 ° (1/4 turn) further
^ Replace
3 - Hydraulic Lifter
^ Pressed into roller rocker finger
4 - Exhaust camshaft
^ Check radial clearance with Plastigage (roller rocker fingers removed). Wear limit: 0.1 mm; Run-out: 0.01 mm (maximum)
5 - Intake camshaft bearing cap
^ Note installation position and numbering
^ Watch position of dowel sleeve (if installed)
6 - Exhaust camshaft bearing cap
^ Note installation position and numbering
^ Watch position of dowel sleeve (if installed)
7 - 5 Nm - tighten 90° (1/4 turn) further
^ Replace
8 - Double bearing cap
9 - Sealing cap
^ Replace
^ To remove, pierce through with screwdriver and pry out
^ To install, drive in using 3202 or suitable metal bar or lever
10 - Bearing cap
^ Lightly coat contact surfaces of front and rear bearing caps with sealant before installation; Refer to Fig. 2
^ Use liquid sealant
^ Refer to Part Supplier
11 - Roller rocker finger
12 - Drive chain
13 - Roller rocker finger
14 - Intake camshaft
^ Checking axial clearance
^ Check radial clearance with Plastigage (roller rocker fingers removed). Wear limit: 0.1 mm; Run-out: 0.01 mm (maximum)

15 - 5Nm tighten 90 ° (1/4 turn) further
^ Replace
16 - Mechanical camshaft adjuster
^ With Valve -1- for camshaft adjustment -N205-
^ Hold in position with special tool 3366 before removing
17 - Rubber/metal seal
^ Replace
18 - Valve cotters
19 - Upper valve spring plate
20 - Valve spring
21 - Valve stem seal
22 - Gasket
^ Replace
23 - Cylinder head
24 - Exhaust valve
^ Do not rework, only lapping is permitted
^ Valve dimensions; Refer to Fig. 1
25 - Intake valve
^ Do not rework, only lapping is permitted
^ Valve dimensions; Refer to Fig. 1
26 - Seal
^ For camshaft position sensor
27 - Camshaft position sensor rotor
^ Note position (notch on camshaft)
28 - Washer
^ Conical
29 - 23 Nm
30 - Camshaft position sensor
31 - 10 Nm
32 - Shaft for roller rocker fingers, intake side
33 - 10 Nm
34 - 10 Nm
35 - Shaft for roller rocker fingers, exhaust side
36 - 55 Nm
37 - Camshaft sprocket
38 - Oil seal
^ For camshaft
39 - O-ring
^ For shaft for roller rocker fingers
^ Replace





Fig. 1 Valve dimensions

Note: Valves must not be reworked. Only lapping is permitted.





CAUTION: Worn exhaust valves with sodium filling must not be disposed of until they have been treated as follows:
^ The valves must be sawn into two sections with a metal saw at a point between the center of the shaft and the valve head. They must not come into contact with water while this is being done. Afterward, throw the valves into a bucket of water (not more than ten at time). Then step back because a chemical reaction occurs when the sodium filling burns.
^ After this treatment the valves can be disposed of in the normal way.





Fig. 2 Applying sealant to bearing cap
- Apply a thin coat of sealant to shaded areas on double bearing cap and on outer bearing cap next to camshaft adjuster. Install bearing caps (watch position of dowel sleeves).

^ Refer to Part Supplier